Technical Field
The present invention concerns a method of erecting a pylon of a wind power installation. The present invention also concerns a heating apparatus for heating an annularly peripherally extending junction region between a tubular pylon segment with a peripherally extending segment wall and a pylon foundation of a wind power installation when building up the wind power installation. The present invention further concerns a lifting apparatus for lifting a pylon segment of a concrete pylon of a wind power installation by means of a crane, a centering bar for fixing to a first pylon segment of a concrete pylon of a wind power installation and for guiding a second pylon segment of the concrete pylon when the second pylon segment is being lowered onto the first pylon segment. The present invention also concerns a work platform apparatus for working at a variable height in a pylon or pylon segment of a wind power installation. The present invention also concerns a heating apparatus for heating an annularly peripherally extending junction region between a tubular pylon segment with a peripherally extending segment wall and a pylon foundation of a wind power installation when building up the wind power installation. The invention also concerns a method of lifting and lowering a pylon segment of a concrete pylon of a wind power installation.
Description of the Related Art
Methods of erecting a pylon of a wind power installation, in particular a concrete pylon, are basically known. Firstly a concrete foundation is provided. A concrete pylon in the finished condition has a plurality of pylon segments. Such pylon segments can be provided in the form of tubular and thus cylinder-like elements, namely in contrast to a cylinder, with a slightly conical shape. When larger pylon diameters are involved, subdivision in the peripheral direction is also considered, so that for example two elements which are approximately semicircular in cross-section, or other part-circular segments, are fitted together.
Firstly one or more pylon segments are placed on the foundation, as the first lowermost tier of the pylon. It is important that that first tier is very carefully oriented, namely levelled off. For that purpose that first segment or plurality of segments are precisely levelled off and firstly at least provisionally fixed in that levelled position in order then to insert a compensating material between the foundation and the lower pylon segment or lowermost pylon segments, that material finally hardening and fixing that levelled orientation.
A problem in that respect is that hardening of the compensating material requires a certain minimum temperature. At low outside temperatures, such as around freezing point, hardening can be significantly prolonged or can completely fail. That results on the one hand in the risk of a compensating material which has poorly or incompletely hardened. On the other hand, waiting for a prolonged hardening period can result in longer stoppage times for, for example, a crane which is required for the installation procedure. Such a crane which has already lifted the first pylon segment or segments onto the foundation remains unused for the duration of the time for hardening of that compensating material. That therefore involves expensive additional stoppage time for the crane.
In addition the pylon is built up successively by further pylon segments being placed on the pylon portion which has been erected hitherto. The operations required for that purpose thus increasingly take place at an increasing height. Thus, in the region of the uppermost tier of the respectively finished pylon portion, a work platform or scaffold is generally set up, on which workers of the erection team can check placement of a new pylon segment. In that case it is desired in particular to check that the respective new pylon segment is arranged at exactly the correct intended position. Thus by means of a crane, each pylon segment is successively lifted approximately to its intended place and a crane operator performs fine positioning of the pylon segment is question. Accurate positioning of each pylon segment is then effected manually by the workers of the erection team on the above-mentioned work platform, that is to say by human strength. In particular the pylon segment in question usually has to be rotated into the correct position. The erection team holds the pylon segment which is oriented by hand in that way in the correct position and the crane operator then slowly lowers the pylon segment while the erection team ensures that it remains in the oriented position. It is to be taken into consideration in that respect that such a pylon segment can weigh between about 5 and 120 t. Therefore very fine positioning has to be effected in spite of using great physical human strength.
That method of placing a further pylon segment is thus complicated, time-consuming and labor-intensive and has a certain susceptibility to error. In addition there is the risk of injuries for the workers on site, in particular the risk of being crushed.
When the new pylon segment is arranged on the pylon which has been erected hitherto the pylon segment must be separated from a cross lifting beam with which the crane lifted the pylon segment. For that purpose carrier loops like steel cables shaped into loops can be fixed to the pylon segment. The lifting beam is then released from those loops, for example being unhooked therefrom, and the steel cable loops as such are then manually removed from the placed pylon segment by the workers on the work platform. That is also complicated and expensive and requires a quite high labor involvement including a suitable work platform at the height of the pylon which has been finished hitherto.
Quite generally attention is directed to the documents U.S. Pat. No. 3,074,564 A, DE 10 2009 023 538 A1 and DE 20 2010 000 868 U1.